Fool broadcast rudely and with confidence (9)

I believe the answer is:

assuredly

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'with confidence' is the definition.
Both the answer and definition are adverbs. Perhaps there's an association between them I don't understand?

'fool broadcast rudely' is the wordplay.
'fool' becomes 'ass' (both can mean a stupid person).
'broadcast' indicates an anagram (letters scattered or cast around).
'rudely' anagrammed gives 'uredly'.
'ass'+'uredly'='ASSUREDLY'

'and' acts as a link.

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I've seen this clue in The Daily Express.

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